Why does water disappear from an open container?

1 Answer
Sep 5, 2017




You have examined the physical process of evaporation.....i.e.

#H_2O(l) rightleftharpoonsH_2O(g)#

Now you had an open system, and the water vapour (or ethanol vapur, or whatever the solvent was) could expand to fill the room, and over 24-48 hours it entirely evaporated. Now you started with a solution, in which there was some involatile solute (what does #"involatile"# mean?).

The solute came out of solution as the water (?) slowly evaporated, to give a solid residue.....

I bet the stuff was copper sulfate, which forms lovely blue crystals of #CuSO_4*5H_2O# on crystallization.....